Differential in roller-mills



(M man L D HARDING DIFFERENTIAL IN ROLLER MILLS.

Patented No?. 10, 1891.

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UNITED STATES PATENT OFFICE.

LEGRAND D. IIARDING, OF COLFAX, VASIIINGTON.

DIFFERENTIAL INV ROLLER-MILLS.

SPECIFICATION forming part of Letters Patent No. 463,049, dated November10, 1891.

Application filed March 16, 1891.

To all whom it may concern.-

Be it known that I, LEGRAND D. I-IARDING, a citizen of the UnitedStates,`residing at Colfax, in the county of Whitman and State ofWashington, have invented certain new and useful Improvements forProducing the Desired Differential in Roller-Mills without the Use ofCounter-Shafts, Pulleys, Belts, Gears, or Tighteners; and I do herebydeclare that the following is a full, clear, and exact description ofthe same, which will enable others skilled in the art to which itappertains to make and use the same, reference being had Y to theaccompanying drawings, which form a part of this specification, inwhich- Figure 1 is a plan view of a roller-mill adapted to Work undermyfprocess, showing the rolls inl position with the upper parts abovethe shafts removed. Fig. 2 is a front elevation of the same with part ofthe front casing removed.

`Heretofore the differential has been acquired by driving one of a pairof rolls atthe desired speed and placing a gear on the shaft thereof oron a shaft connected therewith, the teeth of which connect with a gearof different diameter on or connected with the shaft of the other roll;or by belting from the'shaft of one roll to the shaft of the other roll,using pulleys in any of the Well-known ways; or by driving both fast andslow rolls from aline of shafting by the use of pulleys and belts; or byusing a roll with a suitable annular recess near the middle, incombination with a roll with a suitable annular enlargement, as is shownin my patent, No. 450,014, dated April 7, 1891; or by using a rollprovided with a suitable annular offset at one end, in combination iwith a roll with a suitable annular enlargement, as shown in myapplication for Letters Patent, Serial No. 388,083, dated April 8, 1891.Vhen the gearing is used, a great deal of noise is made thereby, whichis the source of great annoyance, and there is also considerable loss ofpower by the frictional contact of the teeth of the gears. Then beltingis used, there must be idlers and tighteners or cross-belts orcounter-shafts, which make the process complicated and expensive andresult in great loss of power by friction on the journals, arising fromthe pressure of the belts, which alsocause the bearings and journalsSerial No. 385,321. (No model.)

The object of my invention is to produce Y the differential required inroller-mills .for the manufacture of feed and flour Without the use ofbelts, gears, pulleys, or countershafting and without the loss of powerarising from their use, and also without providing` the rolls withoffsets or recesses.

To this end my invention consists of a certain combination of rolls, andin using the stock passing between the rolls and the same power requiredto disintegrate the particles of stock to produce any differentialmotion that may be required between their faces or at their peripheries.

To carry my invention into effect I place four or more rolls inposition, as shown in Figs. 1 and 2, and couple them together by anysuitable means of coupling. These rolls must Vary in diameter sufficientto produce whatever differential may be required between them and theiropposing rolls when each is making an equal number of revolutions in thesame time. In all cases a roll B of large diameter must be opposed by aroll C of small diameter, and each small rollE must have a large one Dopposite.

As before stated, I place four or more rolls in position, in whichIprefer to have about two-thirds of the entire length of those rollsthat are placed in the primary line V (to which power is to be applied)of larger diameter and the remaining one-third of said line V of smallerdiameter. -I then revolve the primary line of rolls by any of thewell-known means, preferably by coupling A to a revolving shaftextending directly from the water-wheel, an engine, or any suitablemotor. I then feed a portion of the stock F to be reduced between thelarge parts B and B of the primary line of rolls V and the small parts Cand C of the secondary line of rolls V', using about twothirds of thestock F, which I distribute throughout the length of all the parts B andand C and B and C so far inuse. I then adjust the rolls so far in use bymeansof handwheels N, so as to reduce the different streams of stockpassing between them (each) to the IOO desired degree of fineness. Atthis point in the process the small parts C and C of the secondary lineof rolls V are driven by their Contact with. the stock passed betweenthem and the large parts B and B of the primary line V (or the primemovers) and move at about the same peripheral speed, the differential sofar acquired being insufficient and beyond the control of the operator.

From the foregoing it may be readily seen that the entire secondary lineof rolls V is now revolving rapidly, and that the differential betweenthe parts D and E, so far unemployed, is very great, and at this pointin the process the large parts D of the secondary line V will berevolving at al high rate of speed at their peripheries and the smallparts E of the first line of rolls V will be moving relatively veryslow, their differential being almost double that required at each pointin the operation and about one-third of the rollsurface running yetunemployed. In ow feed a stream of the remaining stock F between theunemployed rolls D and E to retard the motion of the secondary line Vsufficiently to cause it to revolve at the same speed as the primaryline V, which gives the required differential at all points in theoperation, by reasonof the difference of the diameters of the differentopposing rolls being such as to produce in each pair such difference intheir peripheral movement as may be required for reducing the kind ofstock fed thereto, so long as uniform revolutions are maintained betweentheir respective shafts by the proper distribut-ion of the stock.

It is evident that it may not be necessary to introduce the stockbetween the rolls in the exact order hereinbefore described, but that anapproximate apportionment may be made between all the large and thesmall rolls from the onset, forthe purpose of more evenly guiding thesecondary line of rolls while making the adj ustment.

A striking advantage of my process is that one-half of the rolls areproperly differentially driven by contact with the stock, the same powerbeing used to actuate and govern their movements that is used to reducethe particles, thus saving the expense of all machinery heretofore usedand all annular offsets and recesses heretofore used to guide themovements of one-half the rolls without detriment to the work. I amaware that rolls have heretofore been driven at random by the stockpassing between them and other rolls.

I am also aware that the movement of the secondary roll has been socontrolled by means of suitable annular offsets and recesses, as shownin my patent, No. 450,014, dated April 7, 1891; but I am not aware thatthe method of arranging ordinary straight rolls (each of which is ofuniform diameter throughout its length) so as to control the movementsof all the rolls in the secondary line of such rolls by the relativesize and position of the rolls by the use of the stock operated upon, soas to produce the differentials so essential for granulation inHour-milling, has ever been practiced.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

l. The combination of a primary line of rolls (to which power isapplied) comprising two rolls of larger diameter and one roll of smallerdiameter, each mounted on an independent shaft and each supported inindependent bearings, with the proximate ends of their respective shaftscoupled together and forming a direct line of a secondary line of rollscomprising two rolls of smaller diameter placed opposite the said tworolls of larger diameter in the saidprimary line of rolls and one rollof larger diameter placed opposite the said roll of smaller diameter ofthe said primary line of rolls and each mounted on an independent shaftand each supported in independent bearings and having the proximate endsof their respective shafts coupled together and forming a direct line,lying in the same horizontal plane and having their axes parallel withthe axes of the rolls of the said primary line of rolls and each held infrictional contact with the stream of stock passing between it and itsopposing roll (or mate) in the said primary line of rolls, substantiallyas herein described, and for the uses and purposes herein set forth.

2. The hereindescribed arrangement of rolls of larger diameter and rollsof smaller diameter intwo parallel lines, comprising a primary line ofrolls to which power is to be applied, in which approximately two-thirdsof the aggregate length of the rolls in said primary line are of largerdiameter and the lremainder of smaller diameter and each mounted on anindependent shaft and each supported in in dependent bearings, with theproximate ends of their respective shafts coupled together and forming adirect line, and a secondary line of rolls in which ap- IOO proximatelytwovthirds ofithe aggregate length of the rolls in said secondary lineare of smaller diameter and are placed opposite the rolls of largerdiameter in the aforesaid primary line of rolls and the remainder insaid secondary line are of larger diameter and are placed opposite therolls of smaller diameter in the aforesaid primary line of rolls andeach of the rolls of the said secondary line is mounted on anindependent shaft and each supported in independent bearings with theproximate ends of their respective shafts coupled together and forming adirect line of rolls, the rolls of smaller diameter of the secondaryline being held in frictional contact with the stock passing betweenthem and the rolls of larger diameter of the primary line and the rollsof larger diameter in the secondary line being held in frictionalcontact with the stock passing between them and the rolls of smallerdiameter in the said primary line of rolls, whereby by the relative sizeand position of the several rolls in the,

I Y I l f Y nl series or system the required differential is producedbetween the periphery of each roll and its mate by the Contact of thefaces of the rolls with the intervening stock.

3. The combination of two rolls of large diameter with one roll of smalldiameter to form a primary line of rolls, as and for the uses andpurposes herein set forth. y

4. The combination of two rolls of small di ameter with one roll oflarge diameter, as shown, to form a secondary line of rolls, for theuses and purposes herein set forth.

5. The combination of a primary line of rolls, as shown, with asecondary line of rolls,

LEGRAND D. HARDING.

Witnesses:

R. L. MoCRosKEY, E. K. HANNA.

